Field of the Invention
The present invention relates to voice synthesis control.
Description of the Related Art
Techniques for synthesis of voices obtained from vocalization of given character strings, such as lyrics, have been proposed. For example, Japanese Patent Application Laid-Open Publication No. 2013-205638 discloses a technique for synthesizing a singing voice obtained by singing a music track with lyrics selected by a user.
When a synthesized voice is generated merely by vocalizing pre-prepared lyrics, there is a tendency for the thus generated synthesized voice to be perceived by a listener sounding monotonous. Although this problem can be overcome to some extent by preparing in advance numerous sets of different lyrics, thereby enabling generation of a variety of synthesized voices with different lyrics, there is a problem inherent to this technique in that an excessive work load is incurred in preparing in advance a variety of sets of lyrics.